US3765178A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Afterburner flameholder
Assignee: General Electric Co
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Filing: 1972-09-08
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Granted: 1973-10-16
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Expires: 1992-09-08
Abstract
Abstract An afterburner flameholder for an aircraft gas turbine engine is provided with a continuous annular inlet together with a closely adjacent inlet screen to meter gas flow from the turbine exhaust to a plurality of discrete pilot fuel jets within the flameholder. The wake behind the inlet screen is highly turbulent and operates to minimize temperature gradients existing in the inlet flow. The annular inlet communicates with smooth and uniformly flared flow passages through the flameholder thereby inhibiting local variations in flow velocity which heretofore were caused by sudden disruptions in the flowpath.
Inventors
- 👤 R Hufnagel
- 👤 L Pierce
- 👤 E Sabol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:34
CPC Classifications
F; F23; F23R; F23R3/00; F23R3/02; F23R3/16; F23R3/18; F23R3/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
180 words
In a gas turbine engine of the type having a casing enveloping a compressor, combustor, and turbine in serial flow relation, augmentation is provided by an afterburner comprising: an inner flame ring; an outer flame ring, spaced radially outward and concentric to the inner flame ring, which in cooperation with the inner flame ring defines an annular inlet for receipt of hot gas flow from the turbine, together with an annular outlet; an inlet screen between the inner and outer flame rings closely adjacent the annular inlet for metering the flow between the flame rings wherein the turbulence of the wake behind the screen minimizes circumferential temperature gradients of the gas inflow; means for introducing pilot fuel in discrete jets downstream of the inlet screen; circumferentially spaced apart airfoil type swirl vanes radially extending between the inner and outer flame rings downstream of the pilot fuel means; means for igniting the pilot fuel; means for introducing a main flow of fuel outside the flame rings, and means for maintaining the flame rings in fixed relation relative to the engine casing.
Claim 2
Dependent Claim
180 words
In a gas turbine engine of the type having a casing enveloping a compressor, combustor, and turbine in serial flow relation, augmentation is provided by an afterburner comprising: an inner flame ring; an outer flame ring, spaced radially outward and concentric to the inner flame ring, which in cooperation with the inner flame ring defines an annular inlet for receipt of hot gas flow from the turbine, together with an annular outlet; an inlet screen between the inner and outer flame rings closely adjacent the annular inlet for metering the flow between the flame rings wherein the turbulence of the wake behind the screen minimizes circumferential temperature gradients of the gas inflow; means for introducing pilot fuel in discrete jets downstream of the inlet screen; circumferentially spaced apart airfoil type swirl vanes radially extending between the inner and outer flame rings downstream of the pilot fuel means; means for igniting the pilot fuel; means for introducing a main flow of fuel outside the flame rings, and means for maintaining the flame rings in fixed relation relative to the engine casing.
Claim 3
Dependent Claim
56 words
The afterburner of claim 1 wherein the attaching means comprise a plurality of retaining links pivotally connected at one end to the engine casing; and a plurality of pistons radially disposed in connection to the flame rings and pivotally connected to the other ends of the retaining links, thereby accommodating thermal expansion of the flame rings.
Claim 4
Dependent Claim
24 words
The afterburner of claim 1 wherein: the inner and outer flame rings are conical frustums cooperatively arranged to define an annular rearwardly diverging passageway.
Claim 5
Dependent Claim
25 words
The afterburner of claim 1 wherein: the inlet screen comprises a plurality of circumferentially spaced cylinders extending radially between the inner and outer flame rings.
Claim 6
Dependent Claim
58 words
The afterburner of claim 1 wherein each swirl vane comprises a generally frusto conical main body portion with an integral tail portion extending rearwardly and circumferentially from the main body portion with the sidewalls of the integral tail portion converging rearwardly from tangential intersection with the frusto conical main body into intersection at the swirl vane trailing edge.
Claim 7
Dependent Claim
75 words
The afterburner of claim 5 wherein each swirl vane includes a sharp integral leading edge portion extending forward of the main body portion with the sidewalls of the integral leading edge portion converging forwardly from tangential intersection with the frusto conical main body into intersection at the swirl vane leading edge and wherein: a sidewall of the integral tail portion extends rearwardly and circumferentially beyond the line of intersection of the converging tail portion sidewalls.
Claim 8
Dependent Claim
91 words
The afterburner of claim 1 wherein: the pilot fuel means includes an inlet conduit terminating between the flame rings at a point closely adjacent the leading edge of a swirl vane and having two spaced apart apertures for directing individual jets of pilot fuel on each side of the adjacent swirl vane, and wherein: the main fuel means includes a plurality of inlet conduits terminating radially outward and inward of both flame rings, each conduit of which includes an aperture for directing a jet of main fuel outside the flame rings.
Claim 9
Dependent Claim
115 words
A flameholder comprising: an inner flame ring; an outer flame ring spaced radially outward and concentric to the inner flame ring which in cooperation with the inner flame ring defines an annular inlet and outlet; an inlet screen between the inner and outer flame rings closely adjacent the annular inlet for metering the flow between the flame rings wherein the turbulence of the wake behind the screen minimizes circumferential temperature gradients of the inflow; means for introducing pilot fuel in discrete jets downstream of the inlet screen; circumferentially spaced apart airfoil swirl vanes radially extending between the inner and outer flame rings downstream of the pilot fuel means; and means for igniting the pilot fuel.
Claim 10
Dependent Claim
115 words
A flameholder comprising: an inner flame ring; an outer flame ring spaced radially outward and concentric to the inner flame ring which in cooperation with the inner flame ring defines an annular inlet and outlet; an inlet screen between the inner and outer flame rings closely adjacent the annular inlet for metering the flow between the flame rings wherein the turbulence of the wake behind the screen minimizes circumferential temperature gradients of the inflow; means for introducing pilot fuel in discrete jets downstream of the inlet screen; circumferentially spaced apart airfoil swirl vanes radially extending between the inner and outer flame rings downstream of the pilot fuel means; and means for igniting the pilot fuel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |